Messages in this thread | | | Date | Wed, 1 Mar 2017 01:16:51 +0900 | From | Masami Hiramatsu <> | Subject | Re: kprobes vs __ex_table[] |
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Hi Peter,
On Fri, 24 Feb 2017 10:26:46 +0100 Peter Zijlstra <peterz@infradead.org> wrote:
> One more complication with __ex_table and optimized kprobes is that we > need to be careful not to clobber __ex_table[].fixup. It would be very > bad if the optimized probe were to clobber the address we let the fixup > return to -- or that needs fixups too, _after_ running > __ex_table[].handler().
This gave me a chance to read closer current code, and I found that I made a mistake 5 years ago on kprobe-booster. The commit 464846888d9a ("x86/kprobes: Fix a bug which can modify kernel code permanently") introduced another bug -- which passed the address of copied instruction instead of probing address to search_exception_tables() when preparing kprobe-booster (skips singlestep.)
I'll send a fix patch.
Thank you,
-- Masami Hiramatsu <mhiramat@kernel.org>
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